Avails — what they are and how they are sold
Avails (short for availabilities) are the advertising slots a broadcaster still has open to sell in a given period: which breaks have room, in what programmes and dayparts, at what length, with what audience estimate and at what price.
How the word is used
It names two things that travel together. An avails request is what a buyer sends a seller against a brief — target audience, flight dates, budget, any programmes to include or avoid. An avails list is the answer: the open inventory that fits, priced. Everything after it — negotiation, the media plan, the booking — is built on that list.
Why they are hard to keep accurate
Avails are perishable and they move. A spot sold to another buyer, a programme that overruns, a schedule change, a campaign cancelled the same afternoon — each changes what is genuinely open. When the list is assembled by hand into a spreadsheet and mailed, it starts going stale the moment it is sent, and two buyers can be offered the same break. The usual symptoms are double-booked spots, a booking that has to be walked back, and a seller who discounts inventory that was never at risk of going unsold.
The mirror image of avails is occupancy: what is sold and what is open are the same number read from opposite ends. Which slots command what price is set by daypart and by the rate card.
What a platform changes
Live availability is the difference between a list and a market. In OpenMediaLogic an agency sees the seller's open inventory and its price at the moment it looks, books against it, and the slot leaves the pool for everyone else in the same instant — the way media sales automation works on the sell side and a media buying platform works on the buy side. No avails email, and no second buyer offered the same break.
See also: selling a pool of channels, and pacing for what happens to the inventory once it is booked.